How to use this EV charging cost calculator
Enter your car's usable battery capacity and the charge level you're starting from and charging to. Most drivers charge between about 20% and 80% day to day, which is kinder to the battery and much faster on a DC fast charger. Add your electricity price per kWh from your utility bill, or the price shown at the public charger.
Charging is never 100% efficient: some energy is lost as heat in the charger, cables and battery. The calculator adds those losses, so the cost reflects what your meter or the charger actually bills. Finally, enter your car's efficiency and the fuel economy and gas price of a comparable gas car to see the difference.
The EV charging cost formula
Energy added = battery (kWh) × (end % − start %)
Cost = energy added ÷ (1 − losses) × price per kWh
Worked example: a 75 kWh battery charged from 20% to 80% takes in 75 × 0.60 = 45 kWh. With 10% charging losses, that's 45 ÷ 0.9 = 50 kWh from the grid. At $0.17 per kWh, the charge costs $8.50. At 3.5 miles per kWh, it adds about 158 miles of range, or about 5.4 cents per mile. A 30 mpg gas car would need 5.25 gallons for the same distance, about $18.38 at $3.50 a gallon, so the EV saves roughly $9.88.
Home charging vs. public charging
| Where you charge | Typical price | Cost per 100 miles at 3.5 mi/kWh |
|---|---|---|
| Home, off-peak rate | $0.08–0.12 /kWh | $2.50–3.80 |
| Home, standard rate | $0.15–0.20 /kWh | $4.75–6.35 |
| Public Level 2 | $0.20–0.35 /kWh | $6.35–11.10 |
| DC fast charging | $0.40–0.60 /kWh | $12.70–19.05 |
Prices vary widely by country, state and network, so use your own numbers. The table includes about 10% charging losses. The takeaway: an EV charged mostly at home on an off-peak plan costs a fraction of a gas car per mile, while one charged mostly on DC fast chargers can cost about the same as a fuel-efficient gas car.
What affects EV efficiency?
- Cold weather. Heating the cabin and the battery can cut range by 20–30% in freezing temperatures. Preheating while plugged in helps.
- Speed. Like gas cars, EVs use much more energy at 75 mph than at 55 mph.
- Wheels and tires. Larger wheels and wider tires usually reduce efficiency.
- Charging speed. Losses are usually lowest on Level 2 home charging and higher on slow 120 V outlets.
Frequently asked questions
How much does it cost to charge an electric car at home?
Multiply the energy you add by your electricity rate, plus about 10% for charging losses. Adding 45 kWh at $0.17/kWh costs about $8.50. A full charge of a 75 kWh battery from empty would cost about $14.
Is charging an EV cheaper than gas?
Usually, yes, especially when charging at home. At typical US prices, a 3.5 mi/kWh EV costs about 5 cents per mile versus about 12 cents for a 30 mpg gas car. Relying mainly on DC fast charging narrows or erases the gap.
Why does charging take more energy than the battery holds?
Some energy turns into heat in the charger, the cables and the battery itself, and the car's systems stay awake while charging. Losses are typically 10–15% at home and can be higher on a standard wall outlet.
Should I charge my EV to 100%?
Most manufacturers recommend charging to about 80–90% for daily driving and saving 100% for long trips, because keeping a lithium-ion battery full for long periods speeds up its aging. Check your car's manual; some battery types (LFP) are designed to be charged to 100% regularly.
Results are estimates. Real charging costs depend on your tariff, time of day, charger, temperature and driving style.